OBJECTIVE: To assess the effects of membrane cholesterol on the kinetics of citrate and adenine nucleotide transport across the inner mitochondrial membrane of two lines of Morris hepatomas and with normal mitochondria that have been exogenously enriched with cholesterol in vitro. APPROACH: Mitochondria are isolated from Morris hepatomas 3924A and 16, from host livers and from normal livers of ACI and Buffalo strain rats. Transport of citrate, malate, ATP and ADP is assessed according to both published procedures and via methods applicable specifically to this project. Mitochondria from normal livers will be isolated and enriched with cholesterol via a new "solid-state" molecule transfer methodology developed in this lab. We ask whether the enrichment of mitochondrial membranes with cholesterol, whether during tumor proliferation in the host or via solid-state transfer in vitro, is a sufficient membrane alteration to induce patterns of metabolic behavior that have been observed in mitochondria from a variety of tumors. The underlying rationale for this research is based on the observation that the deregulation and enhanced rate of cholesterol biosynthesis appear to be two of the earliest metabolic alterations noted in virtually every hepatoma examined, and in a large number of other neoplastic cell types, as well.